Another thing we are going to have to bear in mind when formatting our book is that the resolutions of our output devices are very different. Resolution refers to the number of dots in a specified area, and generally speaking, the denser the dots are packed, the better things look. These dots can be ink created by a printer or pixels created by a monitor (or electronic ink on the screen of an e-reader). Your document, too, will have a resolution, and my well be made up of bits and pieces that have there own resolutions (such as if you have a couple of photographs included along with your text).
The most common unit of measurement for resolution differs depending on what sort of device you are outputting to, when you’re printing, dpi is used, which stands for dots per inch; whereas, most commonly, when talking about monitors the, resolution of the entire device is given. So a printer might print an A4 page at 300 dpi; whereas, a kindle keyboard has a resolution 600×800. When talking about graphics, such as a photo, it is common to refer to its resolution in the same way as the output device it is intended to be viewed on i.e. if it it is to be printed, then its dpi is used; whereas, if it is to be viewed on a screen, its entire resolution is given. This poses a bit of dilemma for us as we are outputting to both!
The most important thing for you to understand about resolution is how it relates to size. Basically, the higher the resolution of your document, the bigger it will print/display, and the higher the resolution of the output device, the smaller it will print/display. However, in many situations you can set size as well as resolution, in these cases the image is scaled behind the scenes; and therefore, changing the resolution of the document or output device changes the amount scaling that needs to be done and, therefore, increase or decreases the quality of the image.
So what does all this mean for us and where is the resolution independence that was mentioned it the title of this section? First the good news, unless you screw things up, the text of your novel will be resolution independent, which is to say that it will be displayed/printed optimally no matter what the resolution of the output device.
Unfortunately, it is quite easy to screw things up. We face three main challenges: firstly, though the text is resolution independent, any images contained alongside it aren’t; secondly, though our text may be resolution independent, we can still go awry when specifying how the text is laid out (e.g. when we specify how much we want paragraphs indented); and thirdly, because the printed and electronic versions of our book are going to be different, though we can, for example, specify that we want our title to be 3cm high and expect it to be rendered beautifully in both versions, 3cm takes up a different percentage of the space on a printed page than it does on an e-reader, and this gets even more confusing when you consider that an e-reader can be held both portrait and landscape.
The solution to all these problems is, sadly, in most cases at the moment, to simplify the formatting of the e-book (the printed version can remain as complicated as you like.) This, for most people will be reasonably straight forward, but if you rely a lot on clever layout for some artistic effect, or if you are writing a more academic style book, which uses lots of diagrams and foot notes, it can be tricky and the results disappointing.